org.eclipse.jgit/org.eclipse.jgit/5.5.0.201909110433-r : org/eclipse/jgit/merge/Merger.java

Merger

http://www.eclipse.org/jgit//org.eclipse.jgit: Repository access and algorithms (Eclipse JGit Project)

Eclipse Distribution License (New BSD License)

Andrey Loskutov
Christian Halstrick
Dave Borowitz
David Pursehouse
Gunnar Wagenknecht
Jonathan Nieder
Jonathan Tan
Matthias Sohn
Sasa Zivkov
Terry Parker
Thomas Wolf

/*
 * Copyright (C) 2008-2013, Google Inc.
 * Copyright (C) 2016, Laurent Delaigue <laurent.delaigue@obeo.fr>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.merge;

import java.io.IOException;
import java.text.MessageFormat;

import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.NoMergeBaseException;
import org.eclipse.jgit.errors.NoMergeBaseException.MergeBaseFailureReason;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.ProgressMonitor;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.revwalk.filter.RevFilter;
import org.eclipse.jgit.treewalk.AbstractTreeIterator;
import org.eclipse.jgit.treewalk.CanonicalTreeParser;

Instance of a specific MergeStrategy for a single Repository. /**
 * Instance of a specific {@link org.eclipse.jgit.merge.MergeStrategy} for a
 * single {@link org.eclipse.jgit.lib.Repository}.
 */
public abstract class Merger {
	The repository this merger operates on.
 Null if and only if the merger was constructed with Merger(ObjectInserter). Callers that want to assume the repo is not null (e.g. because of a previous check that the merger is not in-core) may use nonNullRepo(). /**
	 * The repository this merger operates on.
	 * <p>
	 * Null if and only if the merger was constructed with {@link
	 * #Merger(ObjectInserter)}. Callers that want to assume the repo is not null
	 * (e.g. because of a previous check that the merger is not in-core) may use
	 * {@link #nonNullRepo()}.
	 */
	@Nullable
	protected final Repository db;

	Reader to support walk and other object loading. /** Reader to support {@link #walk} and other object loading. */
	protected ObjectReader reader;

	A RevWalk for computing merge bases, or listing incoming commits. /** A RevWalk for computing merge bases, or listing incoming commits. */
	protected RevWalk walk;

	private ObjectInserter inserter;

	The original objects supplied in the merge; this can be any tree-ish. /** The original objects supplied in the merge; this can be any tree-ish. */
	protected RevObject[] sourceObjects;

	If sourceObjects[i] is a commit, this is the commit. /** If {@link #sourceObjects}[i] is a commit, this is the commit. */
	protected RevCommit[] sourceCommits;

	The trees matching every entry in sourceObjects. /** The trees matching every entry in {@link #sourceObjects}. */
	protected RevTree[] sourceTrees;

	A progress monitor.
Since: 4.2/**
	 * A progress monitor.
	 *
	 * @since 4.2
	 */
	protected ProgressMonitor monitor = NullProgressMonitor.INSTANCE;

	Create a new merge instance for a repository.
Params: local – 
           the repository this merger will read and write data on./**
	 * Create a new merge instance for a repository.
	 *
	 * @param local
	 *            the repository this merger will read and write data on.
	 */
	protected Merger(Repository local) {
		if (local == null) {
			throw new NullPointerException(JGitText.get().repositoryIsRequired);
		}
		db = local;
		inserter = local.newObjectInserter();
		reader = inserter.newReader();
		walk = new RevWalk(reader);
	}

	Create a new in-core merge instance from an inserter.
Params: oi –  the inserter to write objects to. Will be closed at the conclusion of merge, unless flush is false.
Since: 4.8/**
	 * Create a new in-core merge instance from an inserter.
	 *
	 * @param oi
	 *            the inserter to write objects to. Will be closed at the
	 *            conclusion of {@code merge}, unless {@code flush} is false.
	 * @since 4.8
	 */
	protected Merger(ObjectInserter oi) {
		db = null;
		inserter = oi;
		reader = oi.newReader();
		walk = new RevWalk(reader);
	}

	Get the repository this merger operates on.
Returns: the repository this merger operates on./**
	 * Get the repository this merger operates on.
	 *
	 * @return the repository this merger operates on.
	 */
	@Nullable
	public Repository getRepository() {
		return db;
	}

	Get non-null repository instance
Throws: NullPointerException – 
            if the merger was constructed without a repository.
Returns: non-null repository instance
Since: 4.8/**
	 * Get non-null repository instance
	 *
	 * @return non-null repository instance
	 * @throws java.lang.NullPointerException
	 *             if the merger was constructed without a repository.
	 * @since 4.8
	 */
	protected Repository nonNullRepo() {
		if (db == null) {
			throw new NullPointerException(JGitText.get().repositoryIsRequired);
		}
		return db;
	}

	Get an object writer to create objects, writing objects to getRepository() 
Returns: an object writer to create objects, writing objects to getRepository() (if a repository was provided)./**
	 * Get an object writer to create objects, writing objects to
	 * {@link #getRepository()}
	 *
	 * @return an object writer to create objects, writing objects to
	 *         {@link #getRepository()} (if a repository was provided).
	 */
	public ObjectInserter getObjectInserter() {
		return inserter;
	}

	Set the inserter this merger will use to create objects.
 If an inserter was already set on this instance (such as by a prior set, or a prior call to getObjectInserter()), the prior inserter as well as the in-progress walk will be released. 
Params: oi –  the inserter instance to use. Must be associated with the repository instance returned by getRepository() (if a repository was provided). Will be closed at the conclusion of merge, unless flush is false./**
	 * Set the inserter this merger will use to create objects.
	 * <p>
	 * If an inserter was already set on this instance (such as by a prior set,
	 * or a prior call to {@link #getObjectInserter()}), the prior inserter as
	 * well as the in-progress walk will be released.
	 *
	 * @param oi
	 *            the inserter instance to use. Must be associated with the
	 *            repository instance returned by {@link #getRepository()} (if a
	 *            repository was provided). Will be closed at the conclusion of
	 *            {@code merge}, unless {@code flush} is false.
	 */
	public void setObjectInserter(ObjectInserter oi) {
		walk.close();
		reader.close();
		inserter.close();
		inserter = oi;
		reader = oi.newReader();
		walk = new RevWalk(reader);
	}

	Merge together two or more tree-ish objects.

Any tree-ish may be supplied as inputs. Commits and/or tags pointing at
trees or commits may be passed as input objects.
Params: tips – 
           source trees to be combined together. The merge base is not
           included in this set.
Throws: IncorrectObjectTypeException – 
            one of the input objects is not a commit, but the strategy
            requires it to be a commit.
IOException – 
            one or more sources could not be read, or outputs could not
            be written to the Repository.
Returns: true if the merge was completed without conflicts; false if the
        merge strategy cannot handle this merge or there were conflicts
        preventing it from automatically resolving all paths./**
	 * Merge together two or more tree-ish objects.
	 * <p>
	 * Any tree-ish may be supplied as inputs. Commits and/or tags pointing at
	 * trees or commits may be passed as input objects.
	 *
	 * @param tips
	 *            source trees to be combined together. The merge base is not
	 *            included in this set.
	 * @return true if the merge was completed without conflicts; false if the
	 *         merge strategy cannot handle this merge or there were conflicts
	 *         preventing it from automatically resolving all paths.
	 * @throws IncorrectObjectTypeException
	 *             one of the input objects is not a commit, but the strategy
	 *             requires it to be a commit.
	 * @throws java.io.IOException
	 *             one or more sources could not be read, or outputs could not
	 *             be written to the Repository.
	 */
	public boolean merge(AnyObjectId... tips) throws IOException {
		return merge(true, tips);
	}

	Merge together two or more tree-ish objects.

Any tree-ish may be supplied as inputs. Commits and/or tags pointing at
trees or commits may be passed as input objects.
Params: flush – 
           whether to flush and close the underlying object inserter when
           finished to store any content-merged blobs and virtual merged
           bases; if false, callers are responsible for flushing.
tips – 
           source trees to be combined together. The merge base is not
           included in this set.
Throws: IncorrectObjectTypeException – 
            one of the input objects is not a commit, but the strategy
            requires it to be a commit.
IOException – 
            one or more sources could not be read, or outputs could not
            be written to the Repository.
Since: 3.5
Returns: true if the merge was completed without conflicts; false if the
        merge strategy cannot handle this merge or there were conflicts
        preventing it from automatically resolving all paths./**
	 * Merge together two or more tree-ish objects.
	 * <p>
	 * Any tree-ish may be supplied as inputs. Commits and/or tags pointing at
	 * trees or commits may be passed as input objects.
	 *
	 * @since 3.5
	 * @param flush
	 *            whether to flush and close the underlying object inserter when
	 *            finished to store any content-merged blobs and virtual merged
	 *            bases; if false, callers are responsible for flushing.
	 * @param tips
	 *            source trees to be combined together. The merge base is not
	 *            included in this set.
	 * @return true if the merge was completed without conflicts; false if the
	 *         merge strategy cannot handle this merge or there were conflicts
	 *         preventing it from automatically resolving all paths.
	 * @throws IncorrectObjectTypeException
	 *             one of the input objects is not a commit, but the strategy
	 *             requires it to be a commit.
	 * @throws java.io.IOException
	 *             one or more sources could not be read, or outputs could not
	 *             be written to the Repository.
	 */
	public boolean merge(boolean flush, AnyObjectId... tips)
			throws IOException {
		sourceObjects = new RevObject[tips.length];
		for (int i = 0; i < tips.length; i++)
			sourceObjects[i] = walk.parseAny(tips[i]);

		sourceCommits = new RevCommit[sourceObjects.length];
		for (int i = 0; i < sourceObjects.length; i++) {
			try {
				sourceCommits[i] = walk.parseCommit(sourceObjects[i]);
			} catch (IncorrectObjectTypeException err) {
				sourceCommits[i] = null;
			}
		}

		sourceTrees = new RevTree[sourceObjects.length];
		for (int i = 0; i < sourceObjects.length; i++)
			sourceTrees[i] = walk.parseTree(sourceObjects[i]);

		try {
			boolean ok = mergeImpl();
			if (ok && flush)
				inserter.flush();
			return ok;
		} finally {
			if (flush)
				inserter.close();
			reader.close();
		}
	}

	Get the ID of the commit that was used as merge base for merging
Returns: the ID of the commit that was used as merge base for merging, or
        null if no merge base was used or it was set manually
Since: 3.2/**
	 * Get the ID of the commit that was used as merge base for merging
	 *
	 * @return the ID of the commit that was used as merge base for merging, or
	 *         null if no merge base was used or it was set manually
	 * @since 3.2
	 */
	public abstract ObjectId getBaseCommitId();

	Return the merge base of two commits.
Params: a –  the first commit in sourceObjects.
b –  the second commit in sourceObjects.
Throws: IncorrectObjectTypeException – 
            one of the input objects is not a commit.
IOException – 
            objects are missing or multiple merge bases were found.
Returns: the merge base of two commits
Since: 3.0/**
	 * Return the merge base of two commits.
	 *
	 * @param a
	 *            the first commit in {@link #sourceObjects}.
	 * @param b
	 *            the second commit in {@link #sourceObjects}.
	 * @return the merge base of two commits
	 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
	 *             one of the input objects is not a commit.
	 * @throws java.io.IOException
	 *             objects are missing or multiple merge bases were found.
	 * @since 3.0
	 */
	protected RevCommit getBaseCommit(RevCommit a, RevCommit b)
			throws IncorrectObjectTypeException, IOException {
		walk.reset();
		walk.setRevFilter(RevFilter.MERGE_BASE);
		walk.markStart(a);
		walk.markStart(b);
		final RevCommit base = walk.next();
		if (base == null)
			return null;
		final RevCommit base2 = walk.next();
		if (base2 != null) {
			throw new NoMergeBaseException(
					MergeBaseFailureReason.MULTIPLE_MERGE_BASES_NOT_SUPPORTED,
					MessageFormat.format(
					JGitText.get().multipleMergeBasesFor, a.name(), b.name(),
					base.name(), base2.name()));
		}
		return base;
	}

	Open an iterator over a tree.
Params: treeId – 
           the tree to scan; must be a tree (not a treeish).
Throws: IncorrectObjectTypeException – 
            the input object is not a tree.
IOException – 
            the tree object is not found or cannot be read.
Returns: an iterator for the tree./**
	 * Open an iterator over a tree.
	 *
	 * @param treeId
	 *            the tree to scan; must be a tree (not a treeish).
	 * @return an iterator for the tree.
	 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
	 *             the input object is not a tree.
	 * @throws java.io.IOException
	 *             the tree object is not found or cannot be read.
	 */
	protected AbstractTreeIterator openTree(AnyObjectId treeId)
			throws IncorrectObjectTypeException, IOException {
		return new CanonicalTreeParser(null, reader, treeId);
	}

	Execute the merge.
 This method is called from merge(AnyObjectId[]) after the sourceObjects, sourceCommits and sourceTrees have been populated. 
Throws: IncorrectObjectTypeException – 
            one of the input objects is not a commit, but the strategy
            requires it to be a commit.
IOException – 
            one or more sources could not be read, or outputs could not
            be written to the Repository.
Returns: true if the merge was completed without conflicts; false if the
        merge strategy cannot handle this merge or there were conflicts
        preventing it from automatically resolving all paths./**
	 * Execute the merge.
	 * <p>
	 * This method is called from {@link #merge(AnyObjectId[])} after the
	 * {@link #sourceObjects}, {@link #sourceCommits} and {@link #sourceTrees}
	 * have been populated.
	 *
	 * @return true if the merge was completed without conflicts; false if the
	 *         merge strategy cannot handle this merge or there were conflicts
	 *         preventing it from automatically resolving all paths.
	 * @throws IncorrectObjectTypeException
	 *             one of the input objects is not a commit, but the strategy
	 *             requires it to be a commit.
	 * @throws java.io.IOException
	 *             one or more sources could not be read, or outputs could not
	 *             be written to the Repository.
	 */
	protected abstract boolean mergeImpl() throws IOException;

	Get resulting tree.
Returns: resulting tree, if merge(AnyObjectId[]) returned true./**
	 * Get resulting tree.
	 *
	 * @return resulting tree, if {@link #merge(AnyObjectId[])} returned true.
	 */
	public abstract ObjectId getResultTreeId();

	Set a progress monitor.
Params: monitor – 
           Monitor to use, can be null to indicate no progress reporting
           is desired.
Since: 4.2/**
	 * Set a progress monitor.
	 *
	 * @param monitor
	 *            Monitor to use, can be null to indicate no progress reporting
	 *            is desired.
	 * @since 4.2
	 */
	public void setProgressMonitor(ProgressMonitor monitor) {
		if (monitor == null) {
			this.monitor = NullProgressMonitor.INSTANCE;
		} else {
			this.monitor = monitor;
		}
	}
}

Params:	oi – the inserter to write objects to. Will be closed at the conclusion of `merge`, unless `flush` is false.
Since:	4.8

Throws:	NullPointerException – if the merger was constructed without a repository.
Returns:	non-null repository instance
Since:	4.8

Params:	tips – source trees to be combined together. The merge base is not included in this set.
Throws:	IncorrectObjectTypeException – one of the input objects is not a commit, but the strategy requires it to be a commit. IOException – one or more sources could not be read, or outputs could not be written to the Repository.
Returns:	true if the merge was completed without conflicts; false if the merge strategy cannot handle this merge or there were conflicts preventing it from automatically resolving all paths.

Params:	flush – whether to flush and close the underlying object inserter when finished to store any content-merged blobs and virtual merged bases; if false, callers are responsible for flushing. tips – source trees to be combined together. The merge base is not included in this set.
Throws:	IncorrectObjectTypeException – one of the input objects is not a commit, but the strategy requires it to be a commit. IOException – one or more sources could not be read, or outputs could not be written to the Repository.
Since:	3.5
Returns:	true if the merge was completed without conflicts; false if the merge strategy cannot handle this merge or there were conflicts preventing it from automatically resolving all paths.

Returns:	the ID of the commit that was used as merge base for merging, or null if no merge base was used or it was set manually
Since:	3.2

Params:	a – the first commit in `sourceObjects`. b – the second commit in `sourceObjects`.
Throws:	IncorrectObjectTypeException – one of the input objects is not a commit. IOException – objects are missing or multiple merge bases were found.
Returns:	the merge base of two commits
Since:	3.0

Params:	treeId – the tree to scan; must be a tree (not a treeish).
Throws:	IncorrectObjectTypeException – the input object is not a tree. IOException – the tree object is not found or cannot be read.
Returns:	an iterator for the tree.

Params:	monitor – Monitor to use, can be null to indicate no progress reporting is desired.
Since:	4.2

/

org.eclipse.jgit/ org.eclipse.jgit/ 5.5.0.201909110433-r/ org/eclipse/jgit/merge/Merger.java